Method of electric forging



(No Model.) E. THOMSON.

v METHOD OF ELECTRIC FORGING.

No. 396,010. Patented Jan. 8, 1889.

WITNESSES. INVENTOR ATTOHNEYJ' UNITED STATES PATENT OrEtcE.

iilllU THOMSON, OF LYNY, ASSIGNOR TO Till!) THOMSON EldllTlilt ll'ELDIXG COMPANY, OF .llOSTON, MASSACill SE'lTlS.

METHOD OF ELECTRiC FORGING.

SPECIFICATION forming part of Letters Patent No. 396,010, dated January 8, 1889. Original application filed May 21, 1836, Serial No. 202,842. Divided and this application filed February 6, 1888. Serial No. 263,153.

To all whom it may concern:

Be it known that I, ELIHU THOMSVN, a citil zen 0f the l nited States, and a resident of Lynn, in the county of Essex and State of Massachusetts, have invented a certain new and useful Method of Electric Forgingof v which the following is a specification.

My present invention relates to a new l method or art in which the heating-power of electric currents is utilized for forging operations, and more particularly in forging operations in the nature of upsetting, wherehy an enlargement is formed upon the ends or sides of metal bars, orother shapes of metals, for a variety of useful purposes. 1

Briefly, my invention consists in passing,

by suitable clamps, a heavy electric current 1 through the part of the har or other piece to he operatmlupon, so as to bring such part to a working-heat irrespective of the other pori tions not to he forced or otherwise treated, i and then shaping by pressure, or by hammering, or other convenient application of force, to eflect an upsetting" operation, and in. such a manner as to move the heated particles in the direction required to give the work the intended or desired form.

The invention may he utilized hy way of formingexpanded heads on large hars, or hy forming heads or projections from the sides of such bars, or hy forming shoulders, necks, or n'ojections of any kind which result: from an endwise compression of an object under the weh'ling' heat of an electric current and a lateral displacement of its heated particles.

Theaccompanying figures will illustrate my invention in some of its applications.

It is assumed that the mnnluctors men tioned herein lead from a source of very heavy electric currents-sueh as a scoomlary coil of an induction-coil of iiew turns whose primary is fed by alternz'iting' cu1a'i, nts-or a i secondary hattcry of large surface, or a dyna1m -machine with very heavy conductors, or an alternator in which the armature has only a few convolutions of heavy comluctor, f or a continuous-current machine of a unipolar type in which the currents are generated i by the revolution oil copper tuhes or disk through a uniform magnetic field. The l'orce (N0 model.)

, head, K, as shown in Fig. 3.

of the current should he under proper control in order that it may he adapted to the size and character of the part to he heated and formed. The same or similar current-generalingideviccs may he used as descrihed in prior applications filed hy me relating to electric wedding.

The mlvani'ae'es of utilizing the heating effects of an electriccurrent are more apparent where the forging or welding operations are directed to some particuiar point or part of the metal har or other piece. and, on the contrary, are nol so apparent in cases where a continiwus metal rod or har is to he suhjccted to the same action throughmit its length, as where the har is to he rolled down or compressed h v rollsthroue'h which it passes continluulsiy.

in the accompanying dmwine's, Figures l and 2 illustrate apparatus for l'ormine' enlarged heads on the ends oi hars in accordance with my illYtllllUll. Figs. 4-, 5, and ti illustrate the formation of heads and collars inaccordancewithiavinvcntion. Figs/"and illustrate apparatus for forming enlargements on the side of metal hars. Fins. it. i l'l,and l2 illustrate l'uriher usciul appliczc tions of this phase of my invention.

in Fig. i, ii is a metal har lirmly held in the fixed clamp 11). l) is a coniactdrlm-h guided so as to he moved in a line with the clamplfl hy a force, as of a spring. H. The har ll ahuts against the contact-hlock l).which is massive and a good conductor of electricity. and whose end in contact with ll mayhc hollow orotherwise Formed, as illustrated in Fig. 2, arethc terminalsoi'lhe heatinn-current.which traverses the fixed hloek E. the metal har ii. and thchiock l). Forconvenience. thcelamp E and the contact I) are located at a short distance from each othcrdhe har ll extendingentirelythrough the clamp E wil h hut a short len th n'ofcctine' from it, u )Oll which theconrs tact; l) hears. On the passage oi the current the end of ihehar I; heats and is upset under the pressurcol' the spring exerted on the contact-hlock l), the result hcinc' an expanded The same principle oioperation is applicahle to raise and form collars or heads or expanded portions on bars at other points than the ends. I11 accomplishing this result it is only necessary to clamp the bar or other metal piece on each side of the part where the bar or piece is to be swelled and then to pass the current through this small section, so as to heat the bar at that point and arrange one or both clamps to be movable toward each other by a pressure of any convenient kind. Thus in Fig. 3, 3 is the bar, as before, held in the fixed clamp E. D is a movable clamp, as in Fig. 1, forced toward clamp E by a spring, S. The clamp D takes hold of the bar at any desired point in its length, thereby determining by its relation to the clamp E the section of the bar or piece which is to be heated and upset. The current bein gon, as before, and the clamp D being moved toward the clamp E in the line of the bar ll, the metal of the bar between the two knobs is heated and the particles are moved outwa1.'dly,in the nature of an upsetting operation, to form an expanded bead, as illustrated in Fig. i. It apparent that this bead or enlargement K may be turned down in a lathe to the form of afinished square collar, as indicated at K K, Fig. (3. In this form the beads willbe useful for preventing end motion of a shaft and bearings. here it is decided to have the expanded or upset portion only on one side of the bar, it is well to inclose the part of the bar operated upon in a non-conducting cover or mold, taking care that it does not fill the space between the clamps D and E and interfere with the end motionof compression. In Fig. 7 such a device shown, and also in section in Fig. 8.

The mold may consist, as shown, of a split tube of fire-clay or hard carbon, which loosely incloses the bar where it is to be heated, and is held in place thereon by bands encircling it, as shown. There is a lateral opening, a, in the mold, into which the bar B can expand or be upset when compressed endwise under the heat produced in it by the heating-current. This is indicated at B, Fig. 8, where a lateral projection on the bar B is shown. This knob or protuberance may be utilized in a variety of ways as, for example, a lateral bar may be welded to the knob by my electric-weldin g process, which forms the sub ject of prior applications; or, the lateral projection b, Fig. 10, having been formed at a distance from the end of a bar, the end may be bent to shape, as shown in Fig. 11, and

finally welded electrically as a ring, as shown in Fig. 12, thus forming a loop on the end of the bar.

It will be apparent that there are many other useful applications of my invention, and I do not therefore confine myself to the format-ion of the precise forms described, as those are only chosen as illustrative of my invention.

I do not claim in this application the invention, broadly, of heating by electric currents, so as to soften a metallic bar or other metal shape, and then shaping the parts so softened, that invention forming the subject of a prior application filed by me May 21, 1886, Serial No. 202,842, and of which application the present is a division.

\Vhat I claim as my invention is 1. The l1erein described art of upsetting metals into any-desired shape, which consists in subjecting the blank to be Worked to the heating action of a heavy electric current sufficient in volume to soften the same and then subjecting the blank to an endwise pressure, substantially as described.

2. The herein-described art or process of electric upsetting, consisting in clamping the bar or blank of metal at two points, leaving a section of the metal between the clamps, passing an electric current through the clamps and section of metal between them so as to soften the metal, then causing said blanks to approach each other in the line of the blank to upset the heated bar or blank between the clamps, substantially as specified.

3. The herein-described method of upsetting metal bars or blanks, which consists in heating the bars or blanks by electric currents traversing them and upsetting the metal bar into the desired shape.

4:. The herein-described process of forming a lateral expansion or projection on a bar or piece of metal, consisting in passing a heavy electric current through the metal blank and then subjecting the blank to pressure while' inclosed in a non-conducting mold having a lateral opening.

Signed at Lynn, in the county of Essex and State of Massachusetts, this 22d day of December, A. D. 1887.

ELIH U THOMSON.

Witnesses: 7

WALTER U. FIsH, OTIs K. STUART. 

